Xpeditions
Grades: K – 12. National Geographic's Xpeditions is an enormous and varied resource for studying the earth and its people. Of particular interest is a 3-D virtual version of the Society's Explorer's Hall, located in Washington, D.C. Users can navigate the virtual museum to visit its many online science exhibits.

Chandra X-Ray Observatory Center
N ASA's Chandra X-ray Observatory, which was launched and deployed by Space Shuttle Columbia in July of 1999, is the most sophisticated X-ray observatory built to date. Chandra is designed to observe X-rays from high energy regions of the universe, such as the remnants of exploded stars.